New Delhi’s Air Pollution Rises Again

This Is How Bad New Delhi's Air Pollution Is

Air pollution in New Delhi was 20 times that of safe limits last week. The Wall Street Journal's Karan Deep Singh carries an air quality monitor for a day to see how dangerous the Indian capital's smog can be. Photo: Karan Deep Singh/The Wall Street Journal

Real-time air quality data from India’s Central Pollution Control Board show that the concentration of PM2.5, tiny particles that can lodge into lungs and cause diseases crossed the 500 mark in central Delhi on Dec. 7– nearly 20 times that of safe limits set by the World Health Organization. The WHO says anything above 25 is harmful to health.

The city’s pollution is caused by emissions from cars and coal-based power plants, the burning of crop stubble and trash and swirling dust from construction sites and roads.

The Supreme Court on Dec. 2 approved a government plan for emergency measures that will kick into action when pollution rises to a P.2.5 level of 300 or more and stays there for 48 hours. When the limit is hit, trucks will be banned from entering the city, construction activities will be stopped and Delhi’s odd-and-even car-rationing program will resume, among other measures.

Officials at the Central Pollution Control Board said November’s pollution was concentrated in Delhi due to slower winds, which weren’t blowing in the usual direction.

“Delhi’s pollution is a result of high emissions from various sources and what you really have to do is cut emissions,” said Sumit Sharma, a fellow at Earth Sciences and Climate Change Division of the Delhi-based Energy and Research Institute who has been studying air pollution in India. “You can’t expect meteorology to work in your favor.”